Slide sleeve for gear shifting and synchronization of power vehicles

ABSTRACT

A sliding sleeve for the gear shift and synchronizing devices of motor vehicles having a clutch gear with coupling teeth and a ring-shaped spring to encircle the teeth of the clutch gear.

United States .Patent [72] Inventors Karl Ashauer;

Dieter Manthey, both of Wolfsburg,

Germany [21] Appl. No. 883,398

[22] Filed Dec. 9, 1969 [45] Patented Oct. 12,1971

[73] Assignee VOLKSWAGENWERK Aktiengesellschaft Wolfsburg, Germany [32]Priority Dec. 10, 1968 [33] Germany [54] SLIDE SLEEVE FOR GEAR SHIFTINGAND SYNCHRONIZATION OF POWER VEHICLES 1 Claim, 5 Drawing Figs.

[52] U.S.Cl l92/53F,

Primary Examiner-Allan D. Herrmann Attorney-Watson, Cole, Grindle &Watson ABSTRACT: A sliding sleeve for the gear shift and synchronizingdevices of motor vehicles having a clutch gear with coupling teeth and aring-shaped spring to encircle the teeth of the clutch gear.

SLIDE SLEEVE FOR GEAR SIIIFTING AND SYNCIIRONIZATION OF POWER VEHICLESThis invention relatesto a sliding sleeve for gear shift andsynchronization installations of motor vehicles, which engage with aninside toothing or teeth into an outside toothing or teeth of asleeve-support arranged fixed on a shaft and which penetrates into thecoupling teeth of the gear that is to be coupled when a particular speedis supposed to be fixed."

It is an object of the invention to provide an installation in which thegear that is to be coupled is smaller than the diameter of the addendumcircle of the inside teeth of the sliding sleeve. Then the shifting pathof the sliding sleeve must be limited by a special stop, so that thesliding sleeve will not run into the mating gear of the speed shiftedthereinto. For this.

purpose stop disks have been known which are placed between the partcarrying the coupling teeth and the pertinent gear, and to be sureeither prior to'the connection of these two parts or else subsequentlywhen the parts are already united with one another or whenever theyconsist of one piece. In the first case, when the connection is to beaccomplished by welding, the stop disk must be made of high-quality rawmaterial so that it can withstand the heat treatment during welding. Inthe other case, it must have inside teeth so' that it can be pushedthrough the gear and can be centered on the other side.

Although such solutions are relatively expensive, they are usedpreferably in the case of constructions which make possible a switchover of the sliding sleeve. In the case of switching over which isfavorable from the point of view of its function and which has alreadyproven itself in practice, the ends of the teeth of the sliding sleevethat have been beveled on both sides in the shifting direction whichends of the teeth play a role in the case of synchronization, will shiftbeyond the coupling teeth of the gear that is to be coupled so that thecoupling teeth in the case of the shifted speed will come to bear withthe full width of their teeth. In order to keep the distance of theshaft bearings'small, the sliding sleeve here must be disposedparticularly close to the mating gear.

It is a further object of the invention to being about the limiting ofthe shifting path of a sliding sleeve of the type described initially,by simple and inexpensive means and to arrange the elements provided forthis purpose within the revolving parts to bring about thesynchronization and shifting of speeds.

For a solution of this object, the invention proposes a circular springencompassing the teeth of the sleeve support-which is fixed in anannular groove cutting the teeth of the sliding sleeve and in the caseof a shifted speed, fits against the ends of the teeth of the slidesupport projecting radially in relation to the spring. The advantage ofthe invention consists in that the utilization of material and thedevelopment of the part, in this case the spring, bringing about thestop of the sliding sleeve, is favorable in comparison to the part ofthe customary designs especially if the diameter of the coupling teethis considerably larger than the assigned or pertinent gear. Thearrangement of the spring furthermore leaves a-minimum ofa slit betweenthe sliding sleeves and the mating gear of the shifted speed. As aresult thereof, a favorable distance'of the bearings for the shaft ofthe gear unit will result.

Advantageously, the spring can consist of wire and may have three radialbulges or the like distributed evenly on the periphery whereby one bulgeis arranged symmetrically in relation to the ends of the spring and theremaining segmentlike sections of the springs are-arranged with theircenter lines on a diameter, which in the case of a fixed'spring, issmaller than the diameter of the addendum circle of the teeth of thesleeve support. Such a spring may serve as a stop in one as well as bothshifting directions of the sliding sleeve. At the same time, it willeffectively cooperate with a recess cutting the teeth of the sleevecarrier which recess depending on the shifting direction of the slidingsleeve and in its neutral position, is arranged either laterally inrelation to the spring and runs out conically in the direction of thespring or has a cylindrical base and extends on both sides of thespring.

Whenever the sliding sleeve is to shift only in one direction, it hasturned out to be particularly advantageous to use a spring which has acircular shape with open ends and which has in the fixed state an insidediameter which is smaller than the diameter of the dedendum of the teethof the sliding sleeve. In this case, it will sufiice inorder to create astop surface for the spring, to develop the teeth of the sleeve carrieror clutch gear on one side with equal ends projecting radially, the

outside diameter of which lies between the inside diameter of the springand the diameter of the dedendum circle of the synchronizationarrangement with a sliding sleeve for only one shifting direction in itsunshifted position,

FIG. 2 is a cross section showing the parts of FIG. I in a shiftedposition of the sliding sleeve,

FIG, 3 is a side view of a spring serving as a stop ring,

FIG. 4 is a partial section of a sliding sleeve for two shiftingdirections in a nohshifted position, and

FIGS is; a partial section of a sliding sleeve for only one shiftingdirection in an unshifted position.

In FIG. 1, the numeral 1 designates a sliding sleeve shiftable axiallyon a clutch gear 5 and having internal teeth 2 in axially slidableintermeshing relationship with the external teeth or s'plines 3 of aclutch gear 5 which is fixed on a shaft 4 of the motorvehicle-synchronizing gear unit. The hub of the clutch gear 5 has beenprolonged on one side in the form of a casing in order to incorporate agear 6 which has been mounted freely rotatable. Gear 6 is smaller thanthe diameter of the addendum circle of the teeth 2 of the sliding sleeve1 and with its mating gear 7 it represents a speed of the synchronizinggear unit. On a specialpart or sleeve'8, connected fixedly with a gear6, coupling teeth 9 have been provided for the purpose of engaging withthe teeth 2 of the sliding sleeve I after a synchronization has beenachieved between the parts that are to be coupled by means of aninterposed synchronizing ring The set of teeth 2 of the sliding sleeve1, has an annular groove 11 therein, which is deep enough so thattherein, segmentlike sections 12 of the annular spring 14, FIG. 3, areprovided at the periphery with radial bulges l3, and ends 13a, can bepressed so that they will be rounded through the teeth 3 of the clutchgear 5. The spring 14 is intended to relax with its sections 12 in arecess 15 of the clutch gear 5 in the case of a shifting of the slidingsleeve 1 and then to strike there against the ends 16 of the teeth 3projecting in relation to the sections 12 and as a result thereof, tolimit the shifting path of the sliding sleeve 1, FIG. 2. For thispurpose the recess I5 has a perpendicular flank 17in relation to theshaft 4 and a generally conical cam surface I8.

FIG. 4 shows the sliding sleeve I provided for the selective coupling oftwo gears. In order to here limit the shifting path of the slidingsleeve 1 in both shifting directions, the recess 15a in the set of teeth3 of the clutch gear 5 has been developed cylindrically. The ends I6 and16a of the set of teeth 3 projecting in relation to the sections 12 ofthe spring l4, are limited in this case also by flanks l7 and which areperpendicular in relation to the shaft I.

The sliding sleeve I shown in FIG. 5 shifts only in one direction. Indeviation from FIG. I, the spring 14a in this case has been developedcircularly so that it always rests with its entire periphery 'on thebottom of he annular groove Ila. This annular groove 11a is so deep thatspring 14a will project with its thickness beyond the dedendum circle ofthe set'of teeth 2 of the sliding sleeve 1, for the greatest partprojecting into the depth of its teeth. The ends 16b of the set of teeth3 of the clutch gear 5, project in the shape'ofti wreath on one side andthey serve with one flank 171) which isper pendicular in relation toshaft 1, as a stop for the spring I421.

The spring 14 or 14a can have both a circular as well as a square shapeas to its cross section. The latter form has a larger stop surface.

We claim:

1. In a motor vehicle a gear-shifting and synchronizing mechanism of theclass in which an internally toothed sliding sleeve is disposed foraxial-shifting movement on an externally toothed clutch gear, into andfrom intermeshing engagement with an axially adjacent externally toothedgear, said mechanism including a circular spring arranged in an annulargroove within said sliding sleeve and extending circumferentially acrossthe internal teeth thereof, and stop means on said clutch gear forengagement with said spring to limit the axial shifting of said slidingsleeve; the improvement wherein he bottom of said groove is of greaterdiameter than the dedendum circle of said internal teeth, the entireexternal periphery of said spring engaging the bottom of said groove atall times, the diameter of the inner periphery of said spring being lessthan that of the dedendum circle of said internal teeth, the externalteeth of said clutch gear adjacent one axial end thereof being encircledby said spring and having radial projections defining said stop meansfor axial engagement by said spring, the outer ends of said projectionslying on a circle, the diameter of which is greater than the internaldiameter of said spring, but less than the diameter of the dedendumcircle of said internal teeth of the sliding sleeve.

1. In a motor vehicle a gear-shifting and synchronizing mechanism of theclass in which an internally toothed sliding sleeve is disposed foraxial-shifting movement on an externally toothed clutch gear, into andfrom intermeshing engagement with an axially adjacent externally toothedgear, said mechanism including a circular spring arranged in an annulargroove within said sliding sleeve and extending circumferentially acrossthe internal teeth thereof, and stop means on said clutch gear forengagement with said spring to limit the axial shifting of said slidingsleeve; the improvement wherein he bottom of said groove is of greaterdiameter than the dedendum circle of said internal teeth, the entireexternal periphery of said spring engaging the bottom of said groove atall times, the diameter of the inner periphery of said spring being lessthan that of the dedendum circle of said internal teeth, the externalteeth of said clutch gear adjacent one axial end thereof being encircledby said spring and having radial projections defining said stop meansfor axial engagement by said spring, the outer ends of said projectionslying on a circle, the diameter of which is greater than the internaldiameter of said spring, but less than the diameter of the dedendumcircle of said internal teeth of the sliding sleeve.